Stop mechanism



E. E. FOSTER.

s10? MECHANISM.

APPLICATION FILED NOV. 13, 1915- Patented J an. 13, 1920. Y

UNITED 'sTATEs PATENT oEEIoE.

' EDWARD E. FOSTER, OF BEVERLY, MASSACHUSETTS, ASSIGNOR To C. C. BLAKE,INCORF PORATED, OF BOSTON, MASSACHUSETTS, A CORPORATION OF NEW YORK.

sror MECHANISM.

Specification of Letters Patent.

Application filed November1 3, 1915. Serial No. 61,396.

To'all wkomz'tmay concern: I

Be it known that I, EDWARD E. FOSTER, a citizen of the United States,residing at Beverly, in the county of Essex and State of Massachusetts,have invented axnew and shaft at a predetermined point in its rota.

tion.

The object-of the present invention is to produce a stop mechanism ofsimplified and im provcd construction. I

o the accomplishment of this object, and

I such others as may hereinafter appear, the --features of theinvention'relate to certain devices, combinations and arrangements ofparts, hereinafter described, and then set forth broadly and in detailin the appended claims, possessing advantages which will be apparent to=tho se skilled in the'art.

The various-features of the invention will be best understood from aninspection of Y the accompanying drawings, illustrating the best form ofthe invention at present known i to the inventor, in which,

Figure 1 is an elevation, partly. in section, of the stop mechanism,showing the position of the parts when the driving shaft is-stopped; anv Fig. 2 is a similar view showing the posi:

tion .of the parts when the driving shaft .is'

rotated. The stop mechanism comprises a shaft 1 to which is splineda'clutch member 2 provided upon opposite sides with frusto-conical faces3 and 4. The face 3 is arranged to engage a similar face 5 formedinternally on a pulley 6 which is loosely mounted on the shaft 1 andwhich is driven from soine suitable source of power through a belt (notshown). face 5 by a spring 7 coiled around the shaft 1 and into sedbetween the clutch member 2 and a col ar 8- on the shaft 1. The clutchmember 2 is normally held away fromthe pulley 6 against the tension ofthe spring 7 by mechanism, who described, which holds the face 4 ontheclutch member engaged I with a brake 9 formed on a bearing for theshaft 1.

In order to The face- 3 is forcedagainst theshift the clutch member 2 onthe shaft 1 out of engagement with the pul- Patented Jan. 1 3',19 20. A

on a stationary pivot 14. The horizontal arm of the bellcra'nk' leverf13is pivoted at 15 to a short link 16 which is pivoted at 17 to thevertical arm 18 of a bell crank lever '19. The bell crank lever 19 ispivoted at 20 to the horizontal arm of a. bell crank lever 21 mounted ona stationary-pivot 22.

The vertical arm of the bell crank lever 21 is provided with a cam roll23 arranged to engage a face cam 24 onthe shaft 1.

With this construction the link 16 and 6 arm 18 form a toggle one arm ofwhich is inverted. The pivots 15, 17 and 20 of this toggle are normallyheld in a line normal to the direction of movement of the clutch memberby a looped spring 25 one end of shaft 1 and the other end of which isconnected to the pivot. 17. When the pivots .15, 1.7 and 20 are in lineor, stated in another moveway, when the toggle is made, any ment of theroll 23 to the right under the influence of the cam 24 will operate tolower the horizontal arm of the bell crank lever 13 exactly as if thehorizontal arm of the bell crank lever 13 were connected by a slot andpin connection to the horizontal arm of the .bell crank lever 21. Themovement of of the cam 24 moves the clutch'member 2 away fromuthe pulley6 and into engagewhich is connected to the bearing for the I is engagedwith the brake 9 thus stopping L used there is a tendency for the shocktrans mitted from the cam to the toggle to break the toggle thuspermitting the shaft to overrun. By employing a toggle having oneinverted arm the three pivots of the toggle are positively locked inalinement during the transmission of the cam movement to the clutchmember thus insuring the stop ping of the shaft at the proper time.

Asshown in Fig. 1 the shaft 1 is disconnected from thevpulley 6. Inorder to clutch the pulley 6 to the shaft 1 the horizontal arm of thebell crank lever' 19 is depressed through a treadle rod 26. This breaksthe inverted toggle thus releasing the clutch member 2 to the influenceof the spring 7 which forces the clutch member 2 into enagement with thepulley 6. The cam roll 23 is also withdrawn from the cam face 24 topermit the rotation of the cam without engagement therewith. Whenl. itis desired to stop the machine the treadle rod 26 is released. If the cam roll 23 is free to return to a low part of the cam face 24 the spring25 remakes the toggle thus resettin the connections between the cam andt e clutch member 2 so that the clutch member 2 is operated by the caminto engagement with the brake. If the cam roll 23 is not free to returnto a low part of the cam but engages.

instead a higher part on the cam than needed to stop the driving shaftat the predetermined point the toggle is not remade but on the cam face.

It will be clear to those sldlled in this 7 class .of devices, and withthe general objects of the present invention in view, that changesmay bemade in the details of structure, the described and illustrated embodi-'ment thereof being intended as an exploita- 'tion of its underlyingessentials, the features whereof are definitely stated in their 'truescope in the claims herewith. What is claimed as new, is':.

1. A stop mechanism, having, H1 combination, a driving pulley, a brake,a clutch member arranged to alternately engage the pulley and brake, aspring for moving the clutch member into engagement with the ulley, andmechanism for positively moving the clutch member into engagement withthe brake comprising a cam and connections between the cam and theclutch member including a toggle, one'arm of which is inverted,substantially as described.

2. A stop mechanism,having, in combination, a driving pulley, a brake, aclutch member arranged to alternately engage the pulle yand brake, aspring for moving the clutch member into engagement with the pulley, andmechanism for positively. moving the clutch member into engagement withthe brake comprising a cam and connections between the cam and theclutch member in cluding a toggle having when the driving shaft isstopped three floating pivots in a line normal to the direction ofmovement of the clutch member, substantially as described. a 3. A stopmechanism, having, in combination, a driving pulley, a brake, a clutchmember arranged to alternately engage the pulle and brake, a spring. formoving the clutc member into engagement with the ulley, and mechanismfor positively movmg the clutch member-into engagement with the brakecomprising a cam and connections between the cam and the clutch memberincluding a; floating bell crank lever, substantially as described.

4. A sto mechanism, having, in combi- 4 nation, a riving pulley; abrake; a clutch member arranged to alternately engage the pulley andbrake; a spring for moving the clutch member into engagement with thepulley; and mechanism for positively mov-' mg the clutch member intoengagement with the brake comprising a cam and connections between thecam and-the, clutch member including a bell crank lever having astationary pivot, a cam roll on its vertical arm and a secondbell cranklever pivoted on its hori zontal arm, a third bell crank leverhaving astationary pivot and its. vertical arm connected to the clutch member,and a link piv- ,oted to the vertical arm and horizontal arm of thesecond and third bell crank levers, respectively, substantially asdescribed.

5. A stop mechanism, having, in combination, adriving pulley; a brake; aclutch member arranged to alternately engage the pulley and brake; aspring for moving the clutch member into engagement with the pulle andmechanism for positively movmg t e clutch member into engagement withthe brake comprising a cam and connections between the cam and theclutch member including a bell crank lever-having a stationary pivot, acam roll on its vertical armand asceond bell crank lever pivoted on itshorizontal arm, a third bell crank lever having a stationary pivot andits vertical arm connected to the clutch member, and a link pivoted tothe free ends of the vertical arm and horizontal armof the second andthird bell crank levers, respectively}, substantially as described.

6. A stop mec anism, having, in combination, a driving ulley, a brake, aclutch member arranged to alternately engage the pulley and brake, aspring for moving the clutch member into engagement with the pulley,mechanism for normally holding the clutch member engaged with the brakeagainst the tension of the spring comprising a cam and connectionsbetween the cam and clutch member including a cam roll and a toggle,manual'means for breaking the toggle to withdraw the cam roll from thecam and release the clutch member to the influence of the spring, andautomatic means for remaking the toggle and restoring thecam roll to theinfluence of the cam when the manual 'means is released, substantiallyas described.

7. A stop mechanism, having, in combination, a driving shaft, a pulleyloosely mounted thereon, a stationary brake, a clutch mem- 10 hersplined on the shaft, yielding means for moving the clutch member intoengagement with the pulley, and positive means for moving the clutchmember into engagement with the brake including a toggle constructed tolock its iv'ots in a line normal to the axis of the shaft during themovement of the clutch member toward the brake, substantially asdescribed.

EDWARD E. FOSTER.

